Red Hat Linux Security Advisories & CVEs
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Latest Red Hat advisories
Medium [CVE-2026-74733] fix pca953x_irq_bus_sync_unlock regmap lock
In the Linux kernel, the following vulnerability has been resolved: gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock Locking is disabled in the regmap config as this driver uses its own lock. This means that all calls to regmap functions (read or write) must hold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do this, and it was therefore possible that multiple threads could cause an incorrect register to be read/written. A previous patch partly fixed this, but only protected the write to the interrupt mask register, and not the read from the direction register. A flaw was found in the Linux kernel's `gpio: pca953x` driver, which manages General Purpose Input/Output (GPIO) expanders. The driver uses its own locking mechanism, but the `pca953x_irq_bus_sync_unlock()` function failed to acquire the necessary lock when performing register operations. This oversight could allow multiple threads to concurrently access and modify registers, leading to incorrect data being read or written. Such a race condition could result in unpredictable system behavior or data corruption. Red Hat severity: Low — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-413. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9. Red Hat does not currently list a fixing RHSA for this CVE.
Medium [CVE-2026-74651] fix OOB read in rtw_get_wpa_ie
In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read in rtw_get_wpa_ie() rtw_get_wpa_ie() reads bytes at fixed offsets into a vendor-specific information element without checking that the element is long enough, causing an out-of-bounds read for a short trailing IE. The function locates a vendor-specific IE (EID 221) with rtw_get_ie() and then compares a 4-byte OUI+type at pbuf + 2 and reads a 2-byte version word at pbuf + 6. Those accesses require the IE body to be at least 6 bytes, but rtw_get_ie() only guarantees that the element fits within the buffer; it does not enforce a minimum body length. A vendor-specific IE whose length byte is 0 to 5, placed at the end of the buffer, therefore makes these reads run past the end of the IE and past the end of the buffer itself. The buffer holds information elements taken from received management frames and from the IE blob passed to rtw_cfg80211_set_wpa_ie(), which is kmemdup'd to its exact length, so the read can run off the end of the allocation. The sibling helpers rtw_get_sec_ie(), rtw_get_wapi_ie() and rtw_get_wps_ie() in this file already reject too-short vendor-specific IEs before their OUI memcmp(); rtw_get_wpa_ie() was never brought in line with them, and needs a minimum of 6 rather than 4 bytes because of the version word. Add the missing length check.
Medium [CVE-2026-74718] fix net namespace reference leak in reload
In the Linux kernel, the following vulnerability has been resolved: devlink: fix net namespace reference leak in reload devlink_nl_reload_doit() calls devlink_netns_get(), which returns a net with a held reference. When the requested namespace differs from the current one and the reload action is not DRIVER_REINIT, the function returns -EOPNOTSUPP without releasing the reference. Add the missing put_net() on this error path. When the `devlink_nl_reload_doit()` function is called, it may fail to release a network namespace reference under specific error conditions. A local attacker could exploit this reference leak to cause resource exhaustion, leading to a Denial of Service (DoS). Red Hat severity: Low — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-911. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel-rt.
Medium [CVE-2026-74642] Fix UAF at delayed release of MIDI2 EPs
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb: Fix UAF at delayed release of MIDI2 EPs The recent fix for UAF in ump_to_endpoint() caused another UAF because it tries to dereference the UMP endpoint object, but this might be executed at a delayed context where the endpoint has been already released. Add private_free to clear the associated data for avoiding the further dereference for delayed releases. This use-after-free (UAF) vulnerability occurs due to a delayed release of MIDI2 endpoints, leading to an attempt to dereference an already freed Universal MIDI Packet (UMP) endpoint object. An attacker could potentially exploit this memory corruption to achieve arbitrary code execution or cause a denial of service. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-825. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel-rt.
Medium [CVE-2026-74635] bound-check glyph index in bit_cursor
In the Linux kernel, the following vulnerability has been resolved: fbdev: bitblit: bound-check glyph index in bit_cursor() bit_cursor() fetches the glyph under the cursor with c = scr_readw(vc_pos); src = vc_font.data + ((c & charmask) * w * height); where charmask is 0x1ff when vc_hi_font_mask is set. The screen buffer value comes directly from scr_readw() and may be larger than the current font's glyph count. Syzkaller triggers this via vcs_write(). The Call Trace shows vcs_write() in vc_screen.c writing an arbitrary 16-bit value with writev() to /dev/vcsa, which vcs_write_buf() in vc_screen.c stores via vcs_scr_writew() without checking charcount. The stored value is later read in bit_cursor() in bitblit.c. When the font is changed from a font with 512 glyphs to a font with 256 glyphs, the screen buffer can retain characters with the high bit set from the previous mode, which could also produce the same out-of-bounds access. Affected products named by the advisory: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat package: kernel-rt.
Medium [CVE-2026-74617] initialise dibs->lock in dibs_dev_alloc
In the Linux kernel, the following vulnerability has been resolved: dibs: initialise dibs->lock in dibs_dev_alloc() dibs->lock is initialised by dibs_dev_add(), but a dibs device can already take interrupts before that call: ism_probe() runs ism_dev_init(), and hence request_irq(), before it calls dibs_dev_add(). No client can have registered a dmb at that point, so no dmb interrupt can occur, but a GID event interrupt can, and ism_handle_irq() takes dibs->lock unconditionally on entry, before it inspects anything else. Initialise the lock in dibs_dev_alloc() instead, so that it is valid as soon as a driver can publish the device to its interrupt handler. The `dibs->lock` was not properly initialized when a dibs device was allocated, allowing a Global ID (GID) event interrupt to occur before the lock was ready. This could lead to the system attempting to acquire an uninitialized lock, potentially causing a system crash and resulting in a Denial of Service (DoS). Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-908. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel-rt.
Medium [CVE-2026-74681] check ibuf_len against rxbuf_len in bulk msg
In the Linux kernel, the following vulnerability has been resolved: usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg ibuf_len is the bulk IN (receive) buffer size, but the EMSGSIZE check in usbio_bulk_msg() compares it against txbuf_len — the bulk OUT endpoint size. Both are taken independently from different endpoints in usbio_probe(), so the check is wrong when they differ. Use rxbuf_len for the IN direction. This matches the buffer that actually holds the response data. A flaw was found in the Linux kernel's USB subsystem, specifically within the `usbio` module. An incorrect buffer size validation occurs in the `usbio_bulk_msg()` function, where the bulk IN (receive) buffer size is mistakenly compared against the bulk OUT endpoint size instead of the actual receive buffer size. This discrepancy can lead to an erroneous size check, potentially causing unexpected behavior or a denial of service when processing USB bulk messages. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-805. Affected Red Hat products: Red Hat Enterprise Linux 10. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel.
Medium [CVE-2026-74702] reject feature changes after endpoint
In the Linux kernel, the following vulnerability has been resolved: vhost-scsi: reject feature changes after endpoint vhost_scsi_setup_vq_cmds() runs from VHOST_SCSI_SET_ENDPOINT and allocates each command's protection scatterlist array (prot_sgl) according to the acknowledged VIRTIO_SCSI_F_T10_PI bit. The command pools are not rebuilt when VHOST_SET_FEATURES changes that bit later. Although virtio feature bits must not change after feature negotiation, vhost_scsi_set_features() currently accepts such a request after the endpoint is active and updates acked_features. Enabling T10-PI after endpoint setup therefore leaves prot_sgl NULL while the I/O path follows the new feature bit.
Medium [CVE-2026-74710] require at least 16 bytes of TX metadata
In the Linux kernel, the following vulnerability has been resolved: xsk: require at least 16 bytes of TX metadata AF_XDP accepts a TX metadata length as small as eight bytes, but every supported request needs the flags plus at least one eight-byte request field. Such short metadata also lets the kernel read beyond the registered area. Require 16 bytes rather than sizeof(struct xsk_tx_metadata) to preserve compatibility with applications that do not use launch-time metadata. A flaw was found in the Linux kernel's AF_XDP (eXpress Data Path) component. An attacker could potentially exploit this out-of-bounds read to gain unauthorized access to sensitive information, leading to information disclosure. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-125. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel-rt.
Medium [CVE-2026-74603] Fix board ID over-read
In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: Fix board ID over-read The EEPROM board ID is a fixed 13-byte field and is not guaranteed to contain a NUL terminator. Passing it directly to devlink_info_version_fixed_put() treats it as a C string and may read beyond the field. Format at most OCP_BOARD_ID_LEN bytes into the existing local buffer before reporting the ID. Use a precision limit because the snprintf() output size alone does not bound the source string scan. When this ID is processed as a C string, it may lead to an over-read beyond its intended memory boundary. This memory corruption could result in information disclosure. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-125. Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9 as not affected.
Medium [CVE-2026-74628] fix use-after-free of the socket by its timers
In the Linux kernel, the following vulnerability has been resolved: net/x25: fix use-after-free of the socket by its timers The x25 timers are armed with mod_timer() and cancelled with timer_delete(), so a pending timer holds no reference on the socket and a cancel does not wait for a callback already running on another CPU. x25_heartbeat_expiry() also rearms unconditionally, so it can reinstall sk->sk_timer after __x25_destroy_socket() has passed its cancel point. The following __sock_put() frees the socket while the timer is still queued, and the next expiry uses freed memory. KASAN reports a slab-use-after-free on the kmalloc-2k object freed by close(). timer_delete_sync() cannot be used here: x25_heartbeat_expiry() and x25_timer_expiry() both reach the cancels from inside the timer they would wait on, through __x25_destroy_socket() and x25_disconnect(). Arm the timers with sk_reset_timer() and cancel them with sk_stop_timer() so that an armed timer owns a reference, and release it in both expiry handlers. Rearm the heartbeat only while sk_hashed(sk) is still true, since __x25_destroy_socket() unlinks the socket before dropping it. Arm the deferred destroy timer the same way and drop its reference in x25_destroy_timer(). Reproduced on net with KASAN, with the heartbeat period shortened so the window recurs.
Medium [CVE-2026-74689] fix slab-out-of-bounds read in vcc_setsockopt
In the Linux kernel, the following vulnerability has been resolved: net/atm: fix slab-out-of-bounds read in vcc_setsockopt() vcc_setsockopt() contained an ineffective optlen check: if (__SO_LEVEL_MATCH(optname, level) && optlen!= __SO_SIZE(optname)) return -EINVAL; If __SO_LEVEL_MATCH(optname, level) evaluated to false (e.g. if the caller passed a mismatched level), the length check optlen!= __SO_SIZE(optname) was short-circuited and bypassed. Execution then fell through to switch(optname), calling copy_from_sockptr() assuming optval contained sufficient space. Furthermore, even if level matched, a cgroup BPF setsockopt filter could shrink optlen after entry. Because copy_from_sockptr() on kernel pointers uses memcpy(), this leads to a KASAN slab-out-of-bounds read when optlen is smaller than the expected structure size. Fix this by using copy_safe_from_sockptr(), which unconditionally validates that optlen is at least the expected size before copying. Also change the local 'value' variable type from 'unsigned long' to 'int' so that SO_SETCLP matches its sizeof(int) ABI encoding on 64-bit systems. An ineffective length check in the `vcc_setsockopt()` function within the Asynchronous Transfer Mode (ATM) network protocol implementation can lead to a slab-out-of-bounds read.
Medium [CVE-2026-74716] Fix locally exploitable BUG_ON in amdxdna_insert_pages
In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages() In amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears VM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM object and then calls madvise(MADV_DONTNEED), the PTEs will be successfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP). When userspace subsequently accesses the memory, drm_gem_shmem_fault() handles the page fault and attempts to map the backing shmem page via vmf_insert_pfn() which calls vmf_insert_pfn_prot(). Because the backing shmem page is normal system memory (pfn_valid(pfn) is true) and the VMA now has VM_MIXEDMAP set, won't this predictably trigger the explicit assertion BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn)) Fix by removing the vm_flags_mod() call and replacing the vm_insert_pages() pre-population with the handle_mm_fault() loop that was already used for the import (dma-buf) path. A flaw was found in the Linux kernel's amdxdna graphics driver. An unprivileged local user could exploit a vulnerability in how the driver handles memory management operations. By performing specific memory mapping and access patterns, a user could trigger an assertion failure, leading to a system crash and a Denial of Service (DoS).
Medium [CVE-2026-74696] fix TFO max_qlen accounting across reuseport migration
In the Linux kernel, the following vulnerability has been resolved: tcp: fix TFO max_qlen accounting across reuseport migration A listener's TCP_FASTOPEN max_qlen stops being accurate and lets through far more pending Fast Open requests than it was configured for. This only shows up with SO_REUSEPORT listener migration, where closing a listener hands its still-pending TFO children over to a surviving one. fastopenq.qlen is charged in tcp_fastopen_create_child() when the child is created and uncharged in reqsk_fastopen_remove() when the handshake completes. The uncharge follows rsk_listener of the request the child points at, and inet_reqsk_clone() has repointed the child at a new request owned by the new listener, so the ++ and the -- land on two different sockets. The new listener's qlen drifts negative and its limit no longer binds. Charge the new listener during migration, like reqsk_queue_migrated() already does for queue->young and queue->qlen. This can lead to a Denial of Service (DoS) by allowing an excessive number of Fast Open requests, potentially exhausting system resources. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-191. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 9. Will not fix / out of support: Red Hat Enterprise Linux 6.
Medium [CVE-2026-74723] reject inline extents without valid headers
In the Linux kernel, the following vulnerability has been resolved: btrfs: lzo: reject inline extents without valid headers [BUG] For a crafted btrfs image, the following KASAN can be triggered when reading an inline lzo compressed file extent: BUG: KASAN: slab-out-of-bounds in lzo_decompress+0x57d/0x700 Read of size 4 at addr ffff888006f2e644 by task btrfs_lzo_inlin/77 Call Trace: dump_stack_lvl+0x5b/0x70 print_report+0xd1/0x610 kasan_report+0xe0/0x110 __asan_report_load_n_noabort+0x13/0x20 lzo_decompress+0x57d/0x700 btrfs_decompress+0x140/0x1c0 uncompress_inline+0x147/0x1b0 btrfs_get_extent+0xb23/0x10a0 btrfs_do_readpage.constprop.0+0x538/0x1ac0 btrfs_readahead+0x32f/0x5f0 read_pages+0x16f/0x850 page_cache_ra_unbounded+0x296/0x490 do_page_cache_ra+0xd9/0x130 page_cache_sync_ra+0x3ee/0x6f0 filemap_get_pages+0x306/0x15c0 filemap_read+0x329/0xd00 btrfs_file_read_iter+0x1f8/0x2b0 vfs_read+0x4ef/0x720 ksys_read+0xf8/0x1d0 __x64_sys_read+0x71/0xb0 x64_sys_call+0x1ab0/0x1b70 do_syscall_64+0x61/0x470 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [CAUSE] For an inline lzo compressed file extent, there should always be one lzo header, recording the total length of the compressed data, followed by one segment header, recording the compressed lzo payload.
Medium [CVE-2026-74596] fs,fsverity: remove check for fsverity being enabled in setattr_prepare
In the Linux kernel, the following vulnerability has been resolved: fs,fsverity: remove check for fsverity being enabled in setattr_prepare() The check that fs-verity is available in the kernel is not necessary here. Filesystems could have fsverity files even without fs-verity enabled. In that case, truncate on fsverity file will succeed, what this check is trying to prevent. The vulnerability is due to the removal of a check in the setattr_prepare() function, which previously verified if fs-verity was enabled. This change allows fsverity files to be truncated even when the fs-verity feature is not active on the filesystem. This could lead to unintended modifications of fsverity protected files, potentially impacting data integrity. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-253. Affected Red Hat products: Red Hat Enterprise Linux 6. Will not fix / out of support: Red Hat Enterprise Linux 6. Red Hat does not currently list a fixing RHSA for this CVE. Affected products named by the advisory: Red Hat package: kernel.
Medium [CVE-2026-74694] fix heap OOB read in NCSI_CMD_SEND_CMD payload length
In the Linux kernel, the following vulnerability has been resolved: net/ncsi: fix heap OOB read in NCSI_CMD_SEND_CMD payload length ncsi_send_cmd_nl() takes the number of bytes to copy from the attacker-controlled ncsi_pkt_hdr.length field of the in-band packet header, while the source buffer is the NCSI_ATTR_DATA netlink attribute whose readable size is nla_len() - sizeof(ncsi_pkt_hdr). The two length sources are never cross-checked: only nla_len() >= sizeof(struct ncsi_pkt_hdr) is enforced. With hdr->length set larger than the attribute payload (up to 65535 against at most 2032 readable bytes), ncsi_cmd_handler_oem() copies past the end of the netlink attribute buffer with unsafe_memcpy(), leaking up to ~64KB of kernel heap memory into the transmitted NCSI command packet. The destination skb is sized by the declared payload, so the write side does not overflow - this is a pure OOB read / information leak, reachable with CAP_NET_ADMIN on systems with a registered NCSI device (e.g. OpenBMC on Aspeed BMC SoCs, where NET_NCSI=y is standard). Reject commands whose declared payload extends past the end of the data attribute. The issue was found by the autokbug dynamic kernel fuzzer at Tencent Yunding Lab. A flaw was found in the Linux kernel's NCSI (Network Controller Sideband Interface) component.
Medium [CVE-2026-74713] bound map allocation in add_range
In the Linux kernel, the following vulnerability has been resolved: vhost_iotlb: bound map allocation in add_range vhost_iotlb_add_range_ctx() only retires an old entry when the table has a non-zero limit, has exactly reached that limit and has VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating entries after reaching their configured limit. Existing vhost devices allocate their IOTLB with max_iotlb_entries from vhost.c, which defaults to 2048 and is tunable by module parameter. Use the caller-provided limit at the allocation point instead of adding a separate default in the common IOTLB helper, and reject non-positive values in vhost paths that can report an error. Other vhost IOTLB users should not create zero-limit tables when entries can be populated from userspace or guest-controlled requests. Add caller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and vhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require at least two entries for vdpa_sim and mlx5 vDPA paths that install full-range mappings, since those mappings are split into two IOTLB entries. Handle full-range mappings in the common helper by checking that the IOTLB can hold both split entries before inserting the first half. This avoids returning an error after leaving a half mapping behind.
Medium [CVE-2026-74731] Skip sub-disable teardown for never-linked sub-schedulers
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Skip sub-disable teardown for never-linked sub-schedulers A sub-scheduler enable can fail before scx_link_sched() links the sched into the hierarchy, e.g. when the parent is already being disabled, and cleanup still runs the full scx_sub_disable(). That is racy against root disable: drain_descendants() is the only ordering between a sub's disable-time task walk and root disable's all-task teardown, and an unlinked sub is invisible to it. Root's teardown can thus run between the never-linked sub's drain and its walk, exiting every task to no scheduler. The walk then trips the membership WARN and re-homes the exited tasks onto the dying hierarchy, a use-after-free. Skip the cgroup ownership reset and the task walk if @sch was never linked, indicated by the empty ->sibling as unlinking only happens later in the same function. The membership WARN remains valid: a linked sub is always waited on by an ancestor's drain. A race condition can occur during the disabling of a sub-scheduler that was never properly linked into the scheduler hierarchy. This issue could potentially result in system instability or denial of service. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-364.
Medium [CVE-2026-74686] Reset tail when preserving queue on deadlock
In the Linux kernel, the following vulnerability has been resolved: rqspinlock: Reset tail when preserving queue on deadlock Currently, the destruction of the waiter queue is suppressed for rqspinlock in cases where a deadlock is detected. Deadlock checks happen relatively frequently (on entry for AA, within 1ms for ABBA), and waiter threads may not be involved in locking scenarios involving deadlocks. Thus, it is useful to not flush the queue and let other waiters take a stab at acquiring the lock after we detect a deadlock and exit. However, we need to follow the same logic as what we did previously for the waitq_timeout label: reset the tail, and if we cannot, signal the next waiter appropriately. In case of deadlocks, this signal would just mark the MCS node as unlocked, and in case of timeouts, it would signal RES_TIMEOUT_VAL. The difference thus is in the value propagated, which decides whether the queue remains active or gets flushed. Not doing the tail reset, and waiting for the next waiter can lead to cases where we are the final waiter, and thus no next waiter arrives, leading to intermittent stalls in this path. Once the next waiter does join, we will be unblocked. In the theoretical case when the next waiter never joins, we risk stalling indefinitely. This can only happen for ABBA deadlocks, since entry into the wait queue is guarded with AA checks.